A low-level spectrometer with a planar low-energy HPGe: shielding arrangement tests and system performance for 210Pb determination in air filter samples

A system for low-energy photon spectrometry using a planar germanium detector with appropriate specifications is presented. A spectrometric background investigation has been carried out with various detector shielding arrangements. The characteristics of the system for measurements of 210Pb in air-particulate matter on filters have been determined.

Accessing and selecting menu items by in-air touch

Is it possible to realize a non-visual, purely tactile version of an icon-based menu? Driven by such question, a hierarchical tactile dock was designed for an array of ultrasound emitters. The icons were conceived as spatio-temporal variable-speed sequences of tactile stimulation points, that are passively perceived as trajectories drawn on the palm of the hand. The recognition rate on four icons largely improved prior performance results obtained by active haptic exploration. As a result, a four-icons set can be used as the first level of a hierarchy of symbols that can be navigated by touch and gesture. The design process, based on controlled recognition experiments and exploration of dis…

Study of background characteristics of a low-level HPGe spectrometer with passive shielding in various configurations

Abstract A low-background germanium spectrometer has been investigated with different combinations of shielding materials in two locations at ground level. In particular, seven shielding configurations have been tested in a room with thick walls and ceiling. The background components, peaks and continuum in the 50–2600 keV energy region, obtained in the several experimental conditions are reported and discussed.

Diverticoli duttali delle ghiandole salivari maggiori.

Un approccio innovativo per la modellazione degli edifici in muratura intelaiata. Applicazione ad un caso di studio

Le strutture in muratura intelaiata rappresentano una parte rilevante delle strutture esistenti e sono ancora largamente adottate come sistema strutturale per la costruzione di edifici residenziali, soprattutto in aree del mondo a forte sismicità non fortemente industrializzate e nelle quali la muratura rappresenta ancora un materiale tradizionale e a basso costo. In questo lavoro viene presentato un approccio per macro-elementi per la valutazione della risposta sismica di strutture in muratura confinata. La complessa interazione tra il telaio e la muratura è simulata mediante un approccio originale in cui il telaio è modellato con aste a plasticità concentrata mentre il contributo della mu…

FISTOLA AORTO-CAVALE SPONTANEA STUDIATA MEDIANTE TC MULTISTRATO ED ANGIOSCOPIA VIRTUALE

Results of the measurements carried out in order to verify the validity of the poisson-exponential distribution in radioactive decay events

Abstract Berkson, examining a series of 250,000 disintegration time intervals, found a significant departure of the distribution from the Poisson-exponential law. Therefore he proposed to repeat the experiment using a large number of intervals and to check the interval recordings by using more than one recording instrument simultaneously. Accepting these suggestions we developed two systems of data collecting provided with different controls. In several experiments we collected data for more than one million decay intervals. The results elaborated using the Pearson ξ 2 test reflect a Poisson process of the radioactive decay events.

CONCENTRATION MEASUREMENTS OF 7Be AT GROUND LEVEL AIR AT PALERMO, ITALY- COMPARISON WITH SOLAR ACTIVITY OVER A PERIOD OF 21 YEARS

Air activity concentrations of (7)Be in Palermo determined for the period January 1995-December 2002 by gamma-ray spectrometric analysis of particulate samples collected on paper filter by a high-volume sampler (approximately 900 m(3) h(-1)) are reported. The temporal behaviour of (7)Be concentration presents the same characteristics already observed in the measurements carried out over the previous 13-year (1982-1994) investigated period. The mean value of 5.06 mBq m(-3) obtained from the analysis of the 4636 particulate samples collected from 1982 to 2002 can be considered a representative value of (7)Be air concentration at ground level in our geographical zone. The comparison of long-te…

Search for Neutrons as Evidence of Cold Fusion

In this paper investigations performed at the University of Palermo in an attempt to reproduce the cold fusion experiment are reported. The search was devoted to detecting neutron emission from palladium electrodes electrolytically charged with deuterium. In no test was neutron emission significantly over the background observed, either in bursts or continuous. Results of a few tests are reported. For the more sensitive test, an upper limit for D(d,n) cold fusion (at 98% confidence level) of {lambda}{sub f} {lt} 3.6 {times} 10{sup {minus}24} fusion/s {center dot} d-d pair is determined.

Determination of 210Pb concentration in the air at ground-level by gamma-ray spectrometry

Abstract 210 Pb activity concentrations in the air of Palermo were determined by γ-ray spectrometric analysis of 323 particulate samples collected in the period September 1995–December 1996. For each sample, the air filtered through a cellulose filter paper was 8600 m 3 on average. The values of the daily activity concentration of 210 Pb were ranging from 136 to 3390 μBq/m 3 .

Applicazione dell' HRCT nella valutazione dello spessore delle vie aeree nella BPCO

Analisi della tollerabilità dell'indagine scialografica.

PAEDIATRIC SIALOLITHIASIS:MDCT AND SIALOGRAPHY ASPECTS. A SINGLE CENTRE EXPERIENCE

HRCT and scleroderma: semiquantitative evaluation of lung damage and functional abnormalities.

This study sought to validate the Warrick score in the assessment of lung involvement in systemic sclerosis (SSc) and correlate the results with functional abnormalities. In addition, we propose the use of high resolution computed tomography (HRCT) indices of alveolitis and fibrosis to discriminate between different stages of the disease.Thirty-one patients with SSc (16 with the diffuse form and 15 with the limited form) underwent functional and HRCT evaluations of the lung. The semiquantitative evaluation of radiological involvement, as proposed by Warrick, provides a score for each lesion based on the severity and the extent of the pulmonary damage. In addition to the total score, indices…